Change post font

Hi,

How can I change post font?

My website is http://ruicruz.forunsbb.com/, i’m using template ocadia.
I’ve search allready on .css but I cannot find anything (or I dont know hot to find it).

Can you tell me how to do this? And btw, how can I use the same font that my Default template (the white and blue, the default WP theme….).

Thank you in advance,
Rui